This invention relates to smoking articles such as cigarettes.
In the manufacture of smoking articles such as cigarettes, design parameters can be varied in order to control properties thereof. For example, properties such as the tobacco smoke delivery profile can be varied in order to control the composition of the tobacco smoke during use of the cigarette. Typical parameters which are varied include the choice of tobacco additives and/or cigarette paper additives, the permeability of the cigarette paper, the composition of the tobacco or blend of smokable materials, the strand width of the smokable material, the filling capacity of the smokable material, the properties of the filter element which is employed, and the like.
An ability to change the smoke delivery profile of the cigarette allows the manufacturer to provide cigarettes exhibiting varying perceived sensory characteristics. Such characteristics can be varied from cigarette to cigarette and/or from puff to puff during use of a particular cigarette.
U.S. Pat. No. 4,328,817 discloses a cigarette rod wherein the packing density of the tobacco decreases continuously along the length of the rod in the direction away from the end which is to be lit. Such cigarettes are proposed as being capable of providing reduced total particulate matter and carbon dioxide deliveries. However, the reference does not propose a modification of the per puff deliveries of such cigarettes. The ability to control the per puff deliveries of cigarettes is desirable in that the user experiences cigarette mainstream smoke in a discrete series of puffs rather than in terms of the total cigarette characteristics. For example, typical cigarettes provide deliveries of tar and nicotine which increase during use thereof. Thus, the smoke delivery profile of a cigarette is such that the user often experiences an undesirable increase in perceived strength from puff to puff.
It would be highly desirable to provide a cigarette which is capable of being manufactured such that the smoke delivery profile thereof can be readily controlled.